Bore gauging device



Oct 23, 1962 J. H. GREENING ETAI.

BORE GAUGING DEVICE 2 She etS-Sheet 1 Filed May 18, 1960 W i 1 a 5 5 M I W M M 3% w Z n F 4w 3 3 @Wx/ w 5 mg W mm? i .C

Oct. 23 1962 J. H GREENING ETAL 3,05

BORE emcme DEVICE Filed May 18, 1960 2 Sheets-Sheet 2 #1;- Pressure V NTOR 3,05%,381 BQRE GAUGlhIG DEVICE John H. Greening, Birmingham, and Robert C. Engie, Invonra, Mich, assignors to Micromatic Hone Corpora= tron, Detroit, Mich, a corporation of Michigan Filed May 18, 196i), Ser. No. 29,832 Claims. (Cl. 51-3-4) This invention relates to air gauging devices for controlling the operation of honing machines and particularly to an air gauging device operable to sense the enlargement of a workpiece bore to a predetermined diameter.

It is an object of the present invention to provide a gauging device operably associated with a honing tool and adapted to repetitively enter the bore being honed by the tool upon each reciprocation thereof without interruption of the honing operation.

It is another object of the present invention to provide a bore gauging device which is operable to automatically control the operation of the honing tool when the workpiece bore has been enlarged to a desired size.

It is still another object of the present invention to provide a gauging device which is rugged in construction, is relatively unaifected by vibration and jarring of the machine and is mounted independently of the honing tool itself to permit convenient interchange of either the honing tool or the gauge without disturbing the other.

It is another object of the present invention to provide an air gauging device which is actuated in response to an increase in back pressure in a pneumatic system and which eliminates the necessity for disabling the gauge from controlling the machine during removal of the gauge from the workpiece bore,

It is still another object of the present invention to provide a gauging device which is capable of being moved through a guide bushing or upper workpiece opening in order to reach the bore to be gauged during the honing operation.

it is a further object of the present invention to provide a gauging device of the above character which is inexpensive of manufacture, convenient to use and highly accurate in operation.

These and other objects and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings wherein:

FIGURE 1 is a perspective view of a honing machine having a gauging device thereon embodying the principles of the present invention;

FIG. 2 is an enlarged fragmentary sectional view of the structure illustrated in FIG. 1 taken along the line 2-2 of FIG. 3, with parts shown schematically and the honing tool shown in the down position;

FIG. 3 is an enlarged sectional view, with parts removed, of the structure illustrated in FIG. 1 taken along the line 3-3 thereof;

FIG. 4 is a sectional view of the structure illustrated in FIG. 2 taken along the line 44- thereof;

PEG. 5 is a schematic view of the pneumatic and electrical control mechanism used in conjunction with the gauging device illustrated in FIGS. 1-4; and

FIG. 6 is a graph showing the back pressure obtained in the gauging device during the honing operation.

Referring now to the drawings, FIGURE 1 shows a honing machine 19 having a column 12 provided with a housing 14 which serves to support a ram 16 for vertical reciprocation. A drive spindle 18 is supported Within the ram 16 for reciprocation about a vertical axis. A honing tool 29, provided with a drive shaft 22, is connected to the lower end of the spindle 18 at 24 and is driven in rotation and reciprocation thereby.

sat the t Patented Oct. 23, 1%.62

The honing machine 1% is additionally provided with a work supporting platform 26 disposed beneath the honing tool 24) and serving to support a fixture 28 which, in turn, positions and holds the workpiece 30. The workpiece 30 is provided with a hardened liner 32, the inner diameter or bore of which is intended to be honed. The liner 32 is positioned beneath an upper bore or opening 34 of slightly greater diameter than the bore to be honed. A mounting plate 36 is fastened to the top of the fixture 28 and is provided with a guide bushing 38 disposed in alignment with the liner 32 and serves to guide the entrance of the tool into the workpiece.

A pair of guide bars 4-0 are positioned on opposite sides of the ram housing 14 and are supported in alignment by means of pairs of apertured housing ears 42 and 44. A generally U-shaped gauge mounting bracket 46 is supported between the lower ends of the bars 40. The mounting bracket 46 and the guide bars 40 are reciprocate-d in a vertical direction by means of a plate '43 fixed to the lower end of the ram 16 and having apertures on opposite sides thereof through which the guide bars 49 freely pass. A pair of adjustable collars 5d are fastened to the guide bars 40 so as to bear against the top of the plate =48 and cause the bars 46 to be raised upon upward movement of the plate 48 and ram 16. Downward movement of the gauge bracket 46 and bars 40 is limited by means of a pair of adjustable collars 52 secured to the bars 46- and engageable with the housing ears 4d. The collars 52 may be set so as to permit the gauging element, which will hereinafter be described, to just enter the work bore and stop, While the tool continues to travel downwardly within the bore. Thus, excessive and undesired movement of the gauge within the bore is eliminated. Downward travel of the bracket 46 is also limited by means of a guide pin 54 carried by the bracket 46. The pin 54 is adapted to enter the guide opening 58 of a bracket 69 secured to the mounting plate 36 by means of screw 62. The pin 54 abuts against an adjustable stop screw 64 held in position in the bracket 6%. The interiitting of the pin 54 and the bracket 6% serves to maintain the mounting bracket 46 in proper alignment relative to the liner 32 and also to eliminate undesired vibratory movement of the gauging element of a gauging arm 66 after the gauging arm 66 has entered the liner 32.

During the reciprocation of the honing tool, a free rod 68 is fed in an axially downward direction to radially advance a plurality of honing stones 7 o extending peripherally out of the body of the honing tool 20. The advance ment of the honing stones 70 is necessary to compensate for the material abraded away from the working faces of the stones 70 and the gradual enlargement of the size of the bore of the liner 3-2. When the bore of the liner 32 has reached a preselected size, it is customary to halt the advancement of the stones 7 ti and thereafter withdraw the honing tool from the workpiece to the retracted posi tion shown in FIG. 1. The device of the present invention provides means for automatically determining when this preselected size has been reached.

The gauging device of the present invention includes the gauge arm 66 which is adapted to enter the bore to be gauged and which is pivotally carried by the bracket 46. Pivotal support for the gauge arm 66 is provided by means of a block 72 which is fastened to the bracket 46 by a pair of clamps 74 and screws 76. The block 72 is provided with a forwardly open notch 78 within which the upper end of the arm 66 is. hung on a pivot pin 80. A spring 82 seated within the block 72. bears against the upper end of the arm 66 above the pivot pin 80, tending to cause the lower end of the arm 66 to move in an outwardly or right-hand direction, as viewed in FIG. 2. The tension of the spring 82 is controlled by adjustable set screws 84 against which the spring 82 is seated. The outward or right-hand movement of the lower end of the gauge arm 66 is limited by means of an adjustable stop member 87 carried hythe block 72. Disposed at the lower end of the gauge arm 66 is an arcuately shaped gauge head 86 having a pair of hardened blocks or fingers 38 and 90 disposed on opposite sides thereof with their centers approximately 125 apart. The blocks 88 and 90 are provided with outer faces 92 and 94, respectively, which are disposed on a common cylinder of a diameter corresponding to the diameter to which it is desired to hone the bore of the liner 32. The blocks 88 and 90 are of hardened steel and not readily subject to abrasive Wear. Disposed intermediate the blocks 88 and 90 is a third or center hardened block or sensing element 96 having an orifice 98 formed on the outer face 100 thereof. The orifice 98 communicates with an elongated passage 102 which extends the length of the arm 66 and communicates with a threaded inlet opening 104. The inlet opening 104 is, in turn, fitted with a flexible air supply conduit or hose 106. Thus, air received under pressure from the conduit 1126 will be emitted from the orifice 98. The outer face 160 of the block 96, and thus the mouth of the orifice 98, is disposed radially inwardly of the cylinder on which the outer faces 92 and 94 are disposed. The amount of this offset or gap may be varied, but it has been found that five onethousandths of an inch will produce satisfactory results. Thus, when the bore has been honed to the desired size, the orifice 98 will be five one-thousandths of an inch from the wall of the bore.

During reciprocation of the honing tool within the liner 32, the gauge head 86 will be inserted into the liner 32 upon each downward reciprocation of the tool. The lower outer edge of the gauge'head is chamfered to facilitate the entry of the head into the liner. The spring 82 biases the outer faces 92 and 94 of the blocks 88 and 90, respectively, against the bore Wall of the liner 32. Under this condition, the wall of the bore opposite the orifice 98 tends to impede the flow of air from the orifice. This results in the development of an increased pressure within the passage 102 and conduit 166, which may be. descriptively termed as a back pressure. As will be subsequently explained in greater detail, a pressure responsive switch is adapted to sense the magnitude of this pressure. span a chord across the bore. Inasmuch as the distance between the blocks 88 and 90 is fixed, the distance in degrees which will be spanned by the blocks 68 and 913 in a given bore will be decreased as the diameter of the bore is increased and the are between the block will become flatter. With this flattening of the are of the work between the hardened blocks 88 and t that portion of the Wall of the bore opposite the orifice 98 will be brought closer to the orifice 98. It will thus be seen that the back pressure of the air attempting to escape from the orifice 98 will be increased as the bore is enlarged so long as the outer blocks 88 and 90 are held against the wall of the bore. The level which the back pressure will reach when a gap of five one-thousandths of an inch (or Whatever other gap may be built into the gauge head) is reached is determinable and the pressure responsive switch may be set to actuate at this pressure for terminating the honing operation or for performing any other desired machine function.

During upward movement of the gauge head 86, the orifice is held away from the upper end of the bore 34 by means of a rib 108 formed on the outer side of the arm 66 to ensure that the gauge will not sense the already enlarged upper bore 34, thus preventing a false reading of the upper bore 34. In cases where the work bore to be finished is immediately below the guide bushing, the rib 108 may be eliminated and a slot machined in the guide bushing opposite the orifice 98 to prevent a false reading of the guide bushing, which is of slightly larger diameter As may be seen in FIG. 4, the blocks 88 and 919 4 than the desired final size. In such a case, it is also possible to eliminate the stop provided by the screw 64 or collars 52 and produce completely coordinated movement of gauge and toolwith no lost motion therebetween. For this purpose, the stop screw 64- is removed, the collars 52 are raised upwardly on the bars and a third set of adjustable collars 53 raised from the position shown in FIG. 1 to a position engaging the underside of the plate 48. FIG. 5 illustrates a suitable control mechanism usable with the gauge head. As may be seen in FIG. 5, the conduit 106' which is connected to the gauge arm 66 is connected to an automatic controller 128. In practice, a Moore Model 88]) automation controller unit, manufactured by Moore Products Company of Philadelphia, Pennsylvania, has been used. The controller includes a pressure regulator 112 adapted to receive air from a supply conduit 114. The pressure regulator 112 is adjustable to regulate the pressure of air supplied to a valve or adjustable restriction 117. The pressure set on the regulator 112 may be read on a gauge 112A. The valve 117 may be regulated to control the amount of air admitted to a conduit 116 communicating with the conduit 108 and from which the air is also free to flow to a pressure responsive diaphragm 118. A pressure gauge 121 indicates the level of air pressure acting against the diaphragm 118 and may be calibrated to display the di mensioned variation of the bore from the final desired size. In initially setting up the gauging apparatus, the gauge head 86 is placed against a gauge ring accurately machined to the desired bore dimension. The pressure which is attained on the gauge 121 is then determined and the switch 120 is then adjusted to be actuated upon an increase in pressure to this magnitude. The actuation of switch 120 is effective to cause closure of its contacts 1219a. The closure of contacts 120:: is effective to energize a relay R1 through conductors 122 and 124 from a source of electrical potential 126. The energizing of relay R1 causes the closure of its contacts R1a to establish a holding circuit therefor and also through the opening of its contacts Rlb to deenergize solenoid S. The solenoid S controls a valve 134 (shown schematically in FIG. 1). The valve 134 in turn controls the flow of hydraulic fluid to a cylinder 136 for advancing or retracting a piston 138 which powers the feed rod 68. Deenergizing the solenoid 8 permits the valve to spring return to a position causing retraction of the piston and thus collapse of the honing stones '70. In addition, the contacts R10 are closed to illuminate a bulb B mounted on the side of the honing machine 10'. It will, of course, be appreciated that the switch may be provided with additional contacts to accomplish automatic retraction of the tool from the workpiece or to perform any other desired function upon the actuation of the switch 120. In addition thereto, the bulb B provides a means for visually indicating to the machine operator that the selected size has been reached.

FIG. 6 shows the fluctuation of the pressure in the con troller 128 resulting from the movement of the gauge head 86 in and out of the liner 32 during its enlargement by the honing tool 20. With each successive entry, the pressure is increased, due to the fact that the orifice 98 is positioned closer to the wall of the liner 32 with each successive entry. When the pressure reaches a level equal to or above the pressure represented by the line 30 in FIG. 6, the switch 120 will be actuated to either visually indicate to the machine operator that size has been reached (by means of the bulb B) or to automatically perform any desired machine function, such as collapsing the honing stones by deenergizing the solenoid S. It should be noted that if it is desired to slightly alter the size of the bore to be honed, the switch 120 may be adjusted to be actuated at a slightly higher or lower pres sure. This is highly desirable in many types of honing operations. For example, in the finishing of cylinder bores, the pistons are first graded as to specific size range within a larger dimensional tolerance. The bores in which the pistons are to be fitted are then finished according to the specific size piston intended to be fitted therein. The differences between the several sizes are such that the switch 120 can be easily adjusted to gauge the desired diameter for each bore.

Because of the fact that the gauge arm 66 and gauge head 86 are disposed substantially on one side of the honing tool and do not encircle the honing tool or its drive shaft, the honing tool 24 may be readily removed from the honing machine for servicing installation of new honing stones, or replacement with another tool. Similarly, the entire gauge may be easily removed by loosening of the clamps 74 and removal of the block 72 together with the gauge arm 66. During the gauging operation, the spring 82 holds the gauging fingers 88 and 90 against the wall or bore of the liner 32 in proper gauging position. However, the adjustable stop 87 may be so set to keep the gauge head 86 in such a position that upon the withdrawal of the gauging device to the position shown in FIG. 1 and its subsequent reinsertion into the workpiece, the chamfered lower surface of the gauge head 86 will engage the outwardly inclined upper end of the guide bushing 38 to cause the gauge head to slide smoothly through the guide bushing 38 and into the workpiece.

:In certain air gauging devices which have been utilized heretofore, a gauge head having a plurality of orifices spaced equally therearound has been utilized. Such a gauge head has necessarily encircled the drive shaft of the honing tool, which has not permitted removal of the honing tool without disturbing the position of the gauge. Furthermore, such previous air gauges have operated by virtue of a drop in air pressure resulting from the gradual movement of the bore wall away from the air emitting orifices of the gauge head. Such a system has necessarily involved the disenabling of the pressure responsive switch upon removal of the gauge head from the bore to be sensed because of the obvious pressure drop which results from the Withdrawal of the head from the closely surrounding wall of the bore being gauged. In the present system, however, the drop in pressure resulting from the withdrawal of the gauge head from the bore is not such as to effect actuation of the pressure responsive switch.

While it will be apparent that the preferred embodiment herein illustrated is well calculated to fulfill the objects above stated, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.

What is claimed is:

1. A bore size control mechanism for use with a honing machine having a rotating and reciprocating honing tool, said mechanism including a. gauging head adapted to be reciprocated in and out of the bore being honed in timed relation to the reciprocation of the honing tool, said gauging head having a pair of spaced fingers adapted to engage the wall of the bore to be gauged at angularly spaced locations, means on said gauging head defining a fluid emitting orifice disposed between said fingers and arranged to direct fluid against the wall of the bore opposite thereto, a fluid pressure system arranged to deliver fiuid to said orifice, means urging said fingers against the bore wall in a direction substantially perpendicular to a line drawn between said fingers, a switch, and means for actuating said switch in response to fiuid pressure developed in said fluid pressure system by the restriction to the escape of fluid from said orifice created by the reduction in distance between said orifice and the bore wall opposite thereto upon the enlargement of the bore to a predetermined size.

2. A bore size control mechanism for use with a honing machine having a rotating and reciprocating honing tool, said mechanism including supporting means adapted to be reciprocated in timed relation to the reciprocation 6 of the honing tool, a gauging arm pivotally supported on said support means, a gauge head on said gauge arm adapted to enter the bore to be gauged, a pair of bore wall engaging surfaces on said gauge head adapted to engage the bore wall at angularly spaced locations less than degrees apart, means pivotally biasing said gauge arm in a direction urging said surfaces against the wall of the bore when said gauge head enters said bore, said gauge head having an orifice between said surfaces adapted to emit air against the wall of said bore when said surfaces are in engagement with the wall of said bore, said orifice being substantially unobstructed when said gauge head is out of said bore, switch means, and means for actuating said switch means when the bore has been enlarged by an amount sufiicient to bring said element to a predetermined position relative to the bore wall opposite thereto.

3. In a honing machine having a reciprocating and rotating honing tool, a bore gauging device, a gauging arm, support means, means for pivotally supporting said gauging arm on said support means, -a gauge head on said gauge arm adapted to enter the bore to be gauged, a pair of bore wall engaging surfaces on said gauge head adapted to engage the bore wall at angularly spaced locations less than 180 degrees apart, means pivotally biasing said gauge arm in a direction urging said surfaces against the wall of the bore when said gauge head enter-s said bore, said gauge head having an orifice between said bore wall engaging surfaces adapted to emit air therefrom against the wall of said bore when said bore wall engaging surfaces are in engagement with aid bore wall, switch means, means for actuating said switch, a fluid pressure system for supplying fluid to said orifice and means responsive to an increase in pressure in said system to a predetermined amount when the bore has been enlarged by an amount sufficient to bring said element to a predetermined position relative to the bore wall opposite thereto.

4. A bore size control mechanism for use with a honing machine having a rotating and reciprocating honing tool, said mechanism including a gauging head adapted to be reciprocated in and out of a bore being honed in timed relation to the reciprocation of the honing tool, a pair of bore wall engaging elements on said gauging head disposed on a common cylinder and angularly spaced apart, said gauging head having a radially outwardly facing orifice spaced radially inwardly of said common cylinder, a fluid pressure system for emitting fluid from said orifice, means for urging said bore wall engaging elements into contact with the wall of the bore when said gauging head enters the bore to intermittently present said orifice to the bore wall, said orifice being substantially unobstructed when said gauge head is out of said bore, and a pressure responsive switch for controlling the operation of the honing machine adapted to be actuated by an increase in pressure in said fluid pressure system to a given amount as a result of the restriction to the escape of fluid from said orifice produced by the reduction in distance between said orifice and said bore wall to a predetermined distance when said bore wall engaging elements are in engagement with said bore wall.

5. A bore size control mechanism for use with a honing machine having a rotating and reciprocating honing tool, said mechanism including a bracket adapted to be reclpr-ocated, in timed relation to the reciprocation of said honing tool, a gauge arm pivotally mounted on said bracket, a gauge head on one end of said gauge arm adapted to enter the bore to be gauged, a pair of bore wall engaging surf-aces on said gauge head adapted to engage the bore wall at angularly spaced locations less than 180 degrees apart, said gauge arm having a portion thereof extending from the point of pivotal support thereof in a direction opposite from said gauge head, a spring biasing said portion toward the axis of rotation of said honing tool to urge the bore wall engaging surfaces of said gauge head against the wall of said bore when said gauge head enters said bore, said gauge head having an orifice bemined amount for actuating said switch when said orifice isybrought to a given distance from the bore wall opposite thereto and the escape of air from said orifice is restricted by a predetermined amount.

References Cited in the file oi this patent UNITED STATES PATENTS Cronipton Aug. 22, 1944- Mennesson Dec. 9, 1952 Van Dorn Apr. 28, 1953 Harris Jan. 28, 1958 

